Turbine



Dec. 11 1923. Y 1,476,801 H. P. DAHLSTRAND TURBINE Original Filed Sept.5. 1916 Patented Dec. i1 1923.

ens erases-earner HANS P. DAHLSTEAND, F \WAUWATUSA, WISCONSIN, ASSIGNGRTO ALL1S--CHALI%EFRS MANUFAGTURIZG-GOMPANY, OF MELVIAUKEIL, 'WISCGNSIKT,OQTEZPORATION OF f nnnriwsnn.

Application-filed September- 5, 1916,3eria1 IEO. 118,57Y. Renewedsepteznbcr. i922. Serial No. 580,5 l8.

An object of the invention is to providean elastic fluid turbine whichissimple and durable in construction and efficient in operation.

' din utilizing'the energy of elastic fluid, sucl' as steam, to itsfullestextent, it has in some cases been found advantageous to usefluidhaving relatively high initial pressure and to expand this fluid toas near ZGXO (absolute pressure) as possible, In prime movers, such asturbines, operated by fluid under such relatively high initialpressures, as well as in those utilizingrlatively large volumes offluid, it has been found that by employing entire or undivided stages oflow pressure, the ,blad'ing. in the low pressure stage must be madeexcessively large in or der to permit eiiicient and complete expansionof the working fluid. The use ofsuch large lading is objectionable dueto the relatively resulting diameter oi the low pressure stage. and alsodue to the enormous stresses set up in the blades while the machine isin operation. L

In order to maintain the size of the blading and of the rotor diameterwithin desirable limits, it has heretofore'been proposed to divide a lowpressure stage into two parts .vhich receive their supply of fluiddirectly from the exhaust of one or more entire initial stages. in oneof the proposed turbines of the prior art embodying a divided lowpressure. stage, the divisions were formed as radial flow sections,while in another the divisions wereformed as axial flow sections thefluid flowed in opposite axial Ten-Brian.

in an axial direction opposite to the direction 01" flow in the lowpressure'turloines.

On account oi the diiiieulty in designing and constructing radial flowturbines, it is more desirable to have ithe divisions of the lowpressure stage formedas axial flow sec tions. It is also desirable .tohave the di-. visions 'tormed as nearly alike as possi is in order toreduce the cost of construction to. a minimum. Another desirable featureis to have all of the stages deliver power to the same shaft and housedwithin a single casing which is devoid oi excessively long steampassages. I I 7 Q In order to accomplish these desirable results thepresent. invention contemplates the provision of-a single,unidirectional, axial flow turbine comprising'one or more high pressurestages and a divided low pressure stage having two or more divisions ofsimilar construction. The divisions of the low pressure stage deliverpower to a shaft which is connnon to all of the stages, and are housedwithina single casing. The low pressure stage divisions receive theirfluid SdPDly directly fromtheexhaust of a stage of higher pressure anddelivertheir exhaust to a common condenser. The blading of the severaldivisions of the low pressure stage is, of the same kind, the divisionsalso being preferably formed of substantially thesame diameter.

A clear conception of an embodiment of the invention be had by referringto the drawing accompanying and forming a part ofthis specification inwhich like reference characters designate the same or similar parts inthe various views.

Fig; 1 is a diagrammatic vertical sectional view through a compound ormultiple expansion. elastic fluid turbine.

Fig. 2 is a diagrammatic transverse V01" tical section through the.turbine disclosed in Fig. 1, the section-being taken along the line 1111 of Fig. 1. looking in thedi- .rection of the arrow. V

-'The compound turbine disclosed coinprises essentiallya plurality ofstages 2, 3, 4, 5.. niountcd upon conunon main shaft (3 which issupported in end hearings in the usual manner. and which is preferablydirectly connected to an electric geii' nl nr or other energy absorber.The stages of the turbine are preferably arranged in successive order,the high pressure stage 2 being iollowed by the intermediate stage 3,which in turn is followed by the first division 4: of the low pressurestage, which is followed by the second eivision 5 of the low pressurestage. The rotor is preferably housed within a single casing 7 which isdivided along a horizontal plane in order to permit access to the rotorbladiugr A suitable end thrust balancing device 9, uct- "uated byelastic fluid, is-provided'at anend Y of the. turbine rotor and is o1.usual construction'.. 1 s r The hi h pressure stage 2 is provided withan an'nuler high pressure chamber 13 7 4 of the low pressure stage isprovided at its inletiend with an annular low pressure chamber'lti whichreceives steam directly from the exhaust 'end ott the intermediate stage3. The second division 5 of the low pressure stage is provided at itsinlet end ,with an annular auxiliary low pressure chamber 17 Y whichcommunicates directly with the low pressure, chamber 15 by a series ofconduits or passages 16. T divisions 4, 5, of the low pressure stagehave their exhaust ends communicating directly-with a common exhaustchamber 18 which communicates with a condenser in the usual manner. 1

' The admission of steam to the high pressure end of the turbine throughthe valves 11, '12, is controlled by means of a speed governor 8'operating upon these valves through a relay -mechun1sm. The relaymechanism. disclosed comprises essentially a regulating valve 19 ofusual form and a servo-motor 20 adapted to actuate the valves 11 12. i

' During the/normal operation of the turbine, elastic fluid, preferablysteam under pressure, is admitted to the high pressure chamber 13through the high pressure inlet valve'll.and pesses from the chamber 13through the high pressure stage 2 to the intermediate pressure chamber14.

FY0111 the intermediate pressure chamber 14L. the steam passes throughthe intermediate stage 3,'being' delivered in a partially expandedcondition to the low pressure'chamber 15. From the low rressure chamber15 a portion of the partially expended steam passes directly through thefirst division 4t of the low pressure stage, while the remainder of thesteam passes through the conduits or pussu-ges 16 into the auxiliarychamber 17, from which this remainder passes through the second division5 of the low pressure stage. The steam after passing through thedivisions 5, is delivered directly into the chamber 18 from which itiswithdrawn into the condenser. It the supply of steam admitted from thechzunber 13 to the high pressure stage 2 is ii'isuliiicient to properlycarry the loud, the by-puss valve 12 is opened and high pressure steamis admitted directly to the intermediate pressure chamber 11 from whichit passes through the intermediate and low pressure stages.

It will be noted that by constructing the compound turbine with dividedlow pres 5 re sta ge, maximum expansion of the steam with minimum lengthof low pressure blading and minimum diameter of low pressure sections,it attainable. The divisions 41, 5, of the low pressure stage mayrcudily be made of: like construction throughout, thereby reducing thecost of construction to a minimum. By providing a single casing for allof the turbine stages, the cost of constructions is still furtherreduced. The provision of relatively short passages between the stagos,also rcduccs the cost of construction by reducing the length of the unitto a minimum and increases the cfiicicncy by avoiding excessive heatradiation. .Vhile the turbine disclosed has it low pressure stagedivided into only two divisions, it will be noted that the division ofthis stage may be extended if desired. It is also immaterial so far asthe present invention is concerned, whether one or more high pr ssi. estages are, employed.

It should be understood that it is not desired to be limited to theexact details of construction shown and described, for obviousmodifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent,-

1. In turbine, a high pressure stage having" an inlet, a plurality oflow pressure stages each communicarting directly with a. commonadmission chamber, and means for admitting high pressure motive fluid tosaid turbine between said high pressure stage inlet and said lowpressure stage admission chamber.

2. In a turbine, a high pressure stage having high pressure admissionchamber, a plurality of low pressure stages cach comm inic:1 ,in;rdirectly with 21v common low pressure admission chamber associated withsaid high pressure stage, and means for ad mitting high pressure motivefluid to said turbine between said admission chambers.

Hi l

sure stages each communicating directly with a common admission chamber,a valve for admitting motive fluid to saidturbine between said highpressure stage inlet and said common low pressure stage admissionchambenand a governor controlling the operation of both of said valves.

4. In a turbine, a high pressure stage having a high pressure admissionchamber provided with high pressure fluid inlet means, a plurality oflow pressure stages each communicating directly with a common lowpressure admission chamber associated with said high pressure stage,'means for admitting high 'essure motive fluid to said turbine betweensaid admission chambers, and a governor cont-rolling the operation ofboth or" said high pressure inlet and admission means.

5. In a turbine, a high pressure stage hav- 'ing an inlet, a pluralityof low pressure stages located at one end of said high'pressure stageand communlcating directly with a common admission chamber, and means"for admitting high pressure motive fluid to said turbine between saidhigh pressure stage inlet and said low'pressure admission chamber.

6. In a turbine, a'high pressure stage having an inlet, a plurality oflow pressure stages communicating directly With a common admissionchamber and with a common exhaust chamber, and means for admitting highpressure motive fluid to said turbine between said high pressure stageinlet and said low pressure stage admission chamber.

7. In a turbine, a high pressure stage hav ing an inlet, a plurality oflow pressure stages located at one end of said high pressure stage andcommunicatmg directly with a common admission chamber and with a commonexhaust chamber, and means for admitting. high pressure motive fluid tosaid turbine, between said high pressure stage inlet and said lowpressure stage admission chamber. q

8 In aturbine, a high pressure stage hav ing an inlet, a plurality oflow pressure stages through which fluid flowsin the same axialdirection, said low pressure stages communicating directly with a commonad-' mission chamber, and means for admit-ting high pressure motivefluid to said turbine between said high pressure-stage inlet andcomprising one type of blades and having an inlet, a plurality of lowpressure stages comprising the same type of blading, said low pressurestages communicating directly with a common admission chamber, and meansfor admitting high pressure motive fluid to said turbine between saidhigh pressure stage inlet and said low pressure admission chamber.

In testimony whereof, the signature of the inventor is aiiixed hereto. 7

HANS P. DAHLSTRAND.

